Polluted air with impacts on human health and ecosystems is transported with the winds over very long distances. Large-scale biomass burning is an important source for polluted air over the northern hemisphere. In 2006, biomass burning occurred on approximately 2 Mha forest and agricultural land in Russia and neighbouring countries. This highly polluted air was transported across northern Europe all the way to Iceland and Svalbard. High air concentrations of black carbon, ozone and high deposition of nitrogen were measured in Scandinavian forests. High concentrations of particulate matter caused health problems. Large-scale wildfires in Russia have continued until today. The Nordic countries and the EU ought to support neighbouring countries in order to restrict wildfires. Important activities are preventing the burning of agricultural waste and fire-prevention activities in forests.